Electric heating device



tional arcing.

-UNITED STATES PATENT OFFICE.

ORA A. COLBY, OF IRWIN, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC 80 MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

Specification of LettersPatent.

ELECTRIC HEATING DEVICE.

' Patented May 16, 1922.

To all whom it may concern:

- Be it known that I, QRA A. COLBY, a citizen of the United States, and a resident of Irwin, in the county of Vestmoreland and State of Pennsylvania, have invented a new and useful Improvement in Electric Heating Dev-ices, of which the following is a specification. I

My inventionrelates to electric heating devices and, particularly, to devices for heat ing iron or steelbars by passing an electric current through them.

One object of my invention is to provide a heating'device that shall heat the bars to be forged by connecting them in circuit with the secondary of a transformer and that shall permit the connecting of a number of bars in circuit with the secondary winding to prevent arcing when a bar is Withdrawn for forging purposes and to effect simultaneous heating of a plurality of bars.

In a heating device constructed in accordance with my invention, a transformer is connected to a supply circuit for supplying energy to the bars 'to be heated. The transformer preferably comprises two primary coils which are mounted on, and linked with, the armature core of thetransformer. A single-turn, open-circuit secondary winding is located between the two primary coils, and contact terminals are connected to the ends of the secondary winding. Resilient clamping members are associated with each contact member for connecting a number of bars in circuit with the secondary winding of the transformer.

By means-of the above structure, a number of bars may be heated simultaneously and, moreover, a bar may be removed for forging p rposes without opening the secondary wiflding, which would cause objec- In the accompanying drawing, Figure 1 is a lan view (the cover being removed) of a eating deviceconstructed in accordance with my invention; Fig. 2 is a sectional view on the line II-II of Fig.1, and Fig. 3 is a partial side elevational view of the device shown in Figs. land 2 (the end plates removed). F V, I Referring to the drawing, the heating device comprises a framework 1 for supporting a transformer 2 and a cover 3 for inclosing the top of the device.

comprises corner angle irons 4 having side The framework 1 sheets 5 attached to them. Near the bottom of the framework 1, angle irons 6 are attached to the angle irons 4 by means of plates 7 for supporting the transformer 2, as shown in Fig. 2 of the drawing. 1

The transformer 2 comprises an annular core member 8, composed 'of laminated steel, vh1ch rests upon the angle irons 6, as shown 1n Fig. 2 of the drawing. Two primary coils 9 and 10 are mounted on, and linked with, the annular core member 8, and a singleturn, open-circuit secondary winding 11 is located between the two primary coils 9 and 10.

Angle irons 12 and 13 are attached to the end sheets ofthe framework 1 near the top of such framework, and a plate 14 is attached to the angle iron 13. The plate 14 and the angle iron 12 serve to support the cover 3. Lugs 15, which are mounted on the angle iron 12 and the plate 14:, serve to mantain the cover in position. The cover 3 is composed of any suitable plates, connected together by means of angle irons.

Contact terminals 16 and 17 are attached to the ends of the secondary winding in any suitable manner, as'by means of the angle members 18. The contact terminals 16 and 17 are further supported upon two insulating plates 19. The insulating plates .19 are mounted upon angle irons 20, which, in turn, are supported upon plates 21. The plates 21 are attached to the end sheets of the framework in any suitable manner, as by means of angle irons 22.

The plates 21 not only serve to support the insulating plates 19 but also to support a pair of resilient clamping members 23 adjacent to each contact terminal. Each clamping member comprises a fulcrum plate 24:, which is directly attached to the plate 21 in any suitable manner, as by means of bolts or rivets, and a wedge member 25, which is pivotally mounted upon a fulcrum plate 24, as shown in Figs. 1 and 2 of the drawing. The wedge members 25 are insulated from the frame of the device in any suitable manner. A spring member 26 is disposed between the lower end of the wedge member 25 and the fulcrum plate 24 for biasing the upper part of such wedge member towards the associated contact terminal.

The bars of steel or iron 30, which are to be heated for'forgingpurposes, are pushed from the left, as shown in the drawing", be-

tween the contact terminals 16 and 17 and the associated clamping members. Two stop members 31 and 32 are located adjacent to the contact terminal 16 for limiting the movement of such bars. Blocks 33, of any suitable shape, are provided for holding the contact terminals 16 and17 in position.

In the above described heating device, the bars of material 30 are held in engagement with the contact terminals 16 and 17 of the secondary winding by means of the clamping members 23. The flow of the transformer secondary current through the bars serves to heat them for forging purposes. It is possible not only to simultaneously heat two bars but it is also possible to forge and work upon one bar while the other bar is being heated. Thus, it is apparent that no objectionable arcing is effected when a bar is Withdrawn for any purpose. 7

Modifications in the device and in the arrangement and location of parts may be made within the spirit and scope of my invention, and such modificationsare intended to be covered by the appended claims.

I claimas my invention:

1. In an electric heating device, the combination comprising a core member, two primary windings associated with'said core member, an open-circuit secondary winding located between said primary windings, and resilient means for holding a plurality of bars in positicin to 'close said secondary winding. I

2. In an electric heating device, the combination comprising an annular core member, two primary coils mounted on said core member, an open circuit secondary winding located between said primary coils, and two resilient clamping devices associated with each endof said secondary winding for holding the bars to be heated.

3. In an electric heating device, the combination comprising an annular core memher, two primary coils mounted on said core member, a single-turn, open-circuit secondary winding located between said primary coils, a stationary contact terminal connected to each end of said secondary winding, and two resilient clamping members associated With each of said contact terminals, said clamping members serving to hold two of the bars to be heated in engagement with said contact terminals.-

4. In an electric 'binationwith an annular core member, two primary coils mounted on, said core member, and a single-turn, open circuit secondary winding located between said primary coils, of a stationary contact terminal connected to each end of said secondary winding and resilient clamping members associated with each of said contact terminals, said clamping members serving toconnect a plurality of the bars to be heated between the two contact terminals.

In testimony whereof, I have hereunto subscribed my name this 4th day of August, 1920.

- ORA A. COLBY.

heating device, the comand linked with, p 

